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प्रश्न
Find the odd one out and give its explanation.
विकल्प
Tinning
Alloying
Anodization
Froth floatation
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उत्तर
Froth floatation
Explanation-
Froth floatation is a method used for the concentration of ores while others are methods used for the prevention of corrosion.
APPEARS IN
संबंधित प्रश्न
What is an alloy?
Tinning : Tin : : Galvanizing : _________
Write two methods of preventing the rusting of iron.
Explain how painting of an iron gate prevents it from rusting.
Explain why Iron sheets are coated with zinc during galvanization.
What special name is given to the corrosion of iron?
Name the metal which is used for galvanising iron.
The corrosion of iron is called ______.
Name five methods of preventing rusting of iron.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of ______.
Brass is an alloy of ______.
A metal X which is resistant to corrosion is produced by the electrolysis of its molten oxide whereas another metal Y which is also resistant to corrosion is produced by the reduction of its oxide with carbon. Metal X can be used in powder form in thermite welding whereas metal Y is used in making cathodes of ordinary dry cells.
- Name the metals X and Y.
- Which of the two metals is more reactive: X or Y?
- Name one ore or metal X. Also write its chemical formula.
- Name one ore of metal Y. Also write its chemical formula.
- Name one alloy of metal X and one alloy of metal Y.
Mention two uses of the following metals and non-metals
Iron
Bronze is an alloy of ______.
What is corrosion? What are necessary conditions for corrosion?
Compare roasting and calcination.
Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
What are the adverse effects of corrosion?
Write three methods of preventing rusting of iron.
Give reason.
A wooden article should be polished.
Explain the term – rusting and give a word equation for the formation of rust. If polished iron nails are kept in three separate test tubes, state the contents in each test tube required, to prove the conditions for rusting.
Observe the following picture and answer the following questions:
- What is rust?
- Write the chemical formula of rust.
- Write the reaction of oxidation of iron at the anode.
- Write the reaction of oxidation of iron at the cathode.
- What is corrosion?
Which of the following method is used to prevent the accumulation of greenish layer on brass due to corrosion?
Find the correlation:
Bronze : ______ :: Tin : Cu+Zn.
Find the odd one out and give its explanation.
Find the odd one out and give its explanation.
Write the name.
An alloy of copper and tin-
Draw a neat labelled diagram.
Electrolysis
Draw a neat labelled diagram.
Anodizing
Give the equation for the formation of rust.
Amalgam is an alloy of ____________.
The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
Gold plated ornaments is the example of ______.
In ______ process a layer of molten tin is deposited on metals.
Describe two changes that are harmful. Explain why you consider them harmful. How can you prevent them?
